RICHMOND, March 4 — They stumbled and bumbled through the regular season, failing to beat the league’s elite and suffering a set of baffling losses to weaker competition. They needed two months to start a winning streak, barely maintained a winning record, and arrived here at the Colonial Athletic Association tournament as an addendum to a four-team story line.

But after three remarkable and highly unexpected days of basketball that rekindled memories of their Final Four run a year ago, the George Mason Patriots find themselves on the brink of an improbable trip back to the NCAA tournament.